الفهرس 
BASIC PHYSICAL PRINCIPALSOnly 14 pages are availabe for public view
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Abstract
Computed tomographic (CT) angiography has been improved significantly with the introduction of new spiral CT scanners, which offer rapid acquisition of isotropic data sets.
A variety of techniques have been proposed for postprocessing of the resulting images.
The most widely used techniques are multiplanar reformation (MPR), thin-slab maximum intensity projection, and volume rendering. Sophisticated segmentation algorithms, vessel analysis tools based on a centerline approach, and automatic lumen boundary definition are emerging techniques; bone removal with thresholding or subtraction algorithms has been introduced. These techniques increasingly provide a quality of vessel analysis comparable to that achieved with intraarterial three-dimensional rotational angiography.
Continuing advances in scanner and image processing technology promise to further enhance both the accuracy and the practicality of CT angiography.
This essay includes a chapter of basic physical principals that help better understanding of basic CT parameters, MDCT system design and scanning parameters.
A second chapter of basic illustrated anatomy of whole human vascular system.
The third chapter including contrast media related issues as chemistry and types of contrast media that can be used in CTA, safety issues of contrast media for CTA including adverse effects and drug interactions, parameters affecting arterial enhancement as physiological and user selectable parameters, instrumentation and technique of contrast media administration and finally clinical contrast medium injection protocols for computed tomographic angiography.
A fourth chapter named postprocessing and data analysis includes rationale for image postporocessing and description of various visualization techniques including methods , advantages ,disadvantages if present and better clinical usage of these techniques.
Techniques described here are Multiplanar Reformations, Curved Planar Reformations, Ray casting techniques include maximum- and minimum-intensity projection (MIP and MinIP, respectively), ray sum, shaded-surface display (SSD), and VR, Segmentation, Bone Subtraction, Vessel Analysis Tools Based on a Centerline Approach and Two-dimensional Transfer Functions.
The last chapter concisely describes clinical application of these techniques as regard image quality, vessel quantification, indications and example protocols for different vascular systems.
A thorough understanding of the spectrum of visualization and measurement techniques as well as a willingness of the radiologist to explore volumetric imaging data is essential for fully realizing the wealth of clinically important information contained within 3D data sets